package com.navcoo.yidaaddproapi.utils;

import com.alibaba.druid.util.StringUtils;
import org.apache.tomcat.util.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.SecureRandom;

public class DESUtil {

    private final static String DES = "DES";

//    public static void main(String[] args) {
//        String data = "我是6";
//        String key = "wang!@#$%";
//        String encryptStr = encrypt(data, key);
//        System.out.println("加密后的字符串:" + encryptStr);
//        String decryptStr = decrypt(encryptStr, key);
//        System.out.println("解密后的字符串:" + decryptStr);
//    }

    /**
     * 加密
     * Description 根据键值进行加密
     *
     * @param key  加密键byte数组
     * @param data 数据
     * @return {@link String}
     */
    public static String encrypt(String data, String key) {
        if (StringUtils.isEmpty(data) || StringUtils.isEmpty(key)) {
            System.out.println("入参为空,data:" + data + ",key=" + key);
            return null;
        }
        try {
            byte[] bt = encrypt(data.getBytes(), key.getBytes());
            String strs = Base64.encodeBase64String(bt);
            return strs;
        } catch (Exception ex) {
            System.out.println("加密遇到错误:");
            ex.printStackTrace();
        }
        return null;
    }

    /**
     * 解密
     * Description 根据键值进行解密
     *
     * @param key  加密键byte数组
     * @param data 数据
     * @return {@link String}
     */
    public static String decrypt(String data, String key) {
        if (StringUtils.isEmpty(data) || StringUtils.isEmpty(key)) {
            System.out.println("入参为空,data:" + data + ",key=" + key);
            return null;
        }
        try {
            byte[] dataNew = Base64.decodeBase64(data);
            byte[] bt = decrypt(dataNew, key.getBytes());
            return new String(bt);
        } catch (Exception ex) {
            System.out.println("解密遇到错误:");
            ex.printStackTrace();
        }
        return null;

    }

    /**
     * Description 根据键值进行加密
     *
     * @param data
     * @param key  加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成加密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }

    /**
     * Description 根据键值进行解密
     *
     * @param data
     * @param key  加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成解密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }

}
